1. Technical Field
Several aspects of the present invention relate to a photoelectric conversion apparatus, a manufacturing method of the photoelectric conversion apparatus, and an electronic device.
2. Related Art
Heretofore, photoelectric conversion apparatuses that are provided with a switching element realized by a thin film transistor that is formed on a substrate and a photoelectric conversion part consisting of a semiconductor film having a chalcopyrite structure that is connected to the switching element are known.
A compound semiconductor thin film that is constituted to include group 11 elements, group 13 elements and group 16 elements is used for the semiconductor film having a chalcopyrite structure. The photoelectric conversion part is constituted by forming this compound semiconductor thin film into a p-type semiconductor film, and forming a p-n junction with an n-type semiconductor film.
In the above 11-13-16 group compound semiconductor, a CuInSe2 film (so-called CIS film) including copper (Cu), indium (In) and selenium (Se), or a Cu(In,Ga)Se2 film (so-called CIGS film) including Cu, In, gallium (Ga) and Se is used. The CIS film is formed by annealing a metal film including Cu and In in a Se atmosphere at about 500° C. The CIGS film is similarly formed by annealing a metal film including Cu, In and Ga in a Se atmosphere.
For example, JP-A-2012-169517 (FIG. 3) discloses an image sensor serving as a photoelectric conversion apparatus in which thin film transistors and the like are formed on a substrate as a circuit part, and photoelectric conversion parts using the abovementioned CIGS film are laminated on the circuit part.
However, there is a problem with the photoelectric conversion apparatus disclosed in JP-A-2012-169517 in that a desired image cannot be obtained due to stray light.
More specifically, with the photoelectric conversion apparatus disclosed in JP-A-2012-169517, when light is incident on the photoelectric conversion apparatus, leakage current flows in the thin film transistors of the circuit part upon light (stray light) being incident on the thin film transistors, causing the circuit to malfunction, and thus a desired image cannot be obtained. In view of this, a shading film is formed by covering the thin film transistors with a metal film, in order to prevent stray light from being incident on the thin film transistors. However, there is a problem in using a metal film as the shading film for preventing stray light from being incident on the thin film transistors. When a metal film is used as the shading film, much of the light incident on the shading film is reflected. The light reflected by the shading film becomes stray light, and is incident on the photoelectric conversion parts directly or after being multiply reflected. When light is incident on photoelectric conversion parts that are at different locations from the photoelectric conversion part on which the light was originally supposed to be incident, the circuit malfunctions, and a desired image cannot be obtained. In view of this, a photoelectric conversion apparatus that is able to obtain desired images is desired.